3 DonationDonors have their current health assessed by the Donor Health Check (DHC)ml of whole blood up to three times a yearHaematocrit or haemoglobin levelTo ensure recipient safety the donor is also screened for health risks that might make the donation unsafe. Donors are examined for risk and signs of transmissible diseases such as:HIV,Malaria,Viral hepatitisVariant Creutzfeldt-Jacob Disease (vCJD)

4 TestingThe blood that is collected is identified for blood type (ABO and Rh), but is also tested to minimise the risk of transmissible infections. The World Health Organisation recommends four core tests as a minimum:-Hepatitis B Surface Antigen-Antibody to Hepatitis C-Antibody to HIV, usually subtypes 1 and 2-Serology for SyphylisFor patients with specific risks from transfusion, the blood may undergo further processing:Leukoreduction is the removal of white blood cells by filtration, after which the blood product is less likely to cause alloimmunization, febrile reactions, CMV infections, and platelet refractoriness.Irradiation, helps to inactivate pathogens (viruses, bacteria and parasites), as well as inactivating white blood cells to prevent graft-versus-host disease

5 TreatedAll blood components used in the UK and Ireland since October have been leucodepletedMicroaggregate-free blood is used to prevent reactions to leucocyte and platelet antigensWashed red cells usually have haematocrits of 70-80% and a volume of about 180ml.Saline washing removes residual plasma (98%), and reduces the concentration of leucocytes, platelets and cellular debris.Can only be stored for 24 hr at 1-6 ̊C.

7 StorageThe most commonly used solution in the UK is SAGM, which contains sodium chloride, adenine, glucose and mannitol.Short-term storage of blood relies on a combination of refrigeration and the addition of preservatives.Standard temperature used is 1°- 6°CAcid-citrate- dextrose (ACD), citrate-phosphate-dextrose (CPD) or citrate-phosphate-double dextrose (CP2D), the storage is limited to 21 daysCitrate-phosphate-dextrose-adenine (CPDA1) this can be extended to 35 days.Red blood cells can be stored for much longer periods, even up to 10 years, by freezing (cryopreservation)The units are then placed in special sterile containers and frozen to below -60°C

8 Issues with storage GranulocytesBecome non-functional after 24 hours of storageSome lymphocytes may remain viable for several weeksPlatelet function declines to zero after only 48 hours of storageOxygen affinity:Stored blood has depleted levels of 2,3 Diphosphoglycerate (DPG)Coagulation:Stored blood contains an anticoagulantThe labile coagulation factors V and VIII have a 50% decline in activity within the first 72 hours

9 continued…..Temperature: The optimum storage temperature of 2°- 6°C is well below normal body temperatureElectrolytes: Constant leak of potassium out of cells and levels can exceed 30mmol/lCalcium: Each unit of blood contains approximately 3g citrate, which binds ionized calciumAcid/Base: During storage there is a gradual accumulation of lactic acid which can result in an acid load of mmol/l and a resultant fall in pH

10 RBCWhole blood is rarely used, the collected blood is therefore fractionated into its respective componentsPacked Red cells: A bag of RBCs have a haematocrit of between 60-70%The main indications for transfusion is the correction of anaemia or replacement in acute haemorrhage,A single unit of red blood cells will typically increase the Hb by 1g/dl.

11 GranulocytesIndicated for life-threatening infections in neutropenic cancer patientsCollected by apheresis (filtration), and can only be stored for 24 hours at degree centigradeRequire cross match due to presence of RBCIrradiated

12 Platelets Circulatory life span of 8-14 daysPlatelets for transfusion are collected in two ways:1. Pooled platelets2. Apheresis platelets (equivalent of 4-6 units of random donor platelets)Platelets last for 3-5 days if stored at 22 ̊C and at a pH of between 6.2 and 7.8Each bag has a volume of mlPlatelet count in pack: > 2.4x1011 per adult doseThe risk of transmission of bacterial infection is higher with platelet transfusions than red cells

13 Fresh frozen plasmaIt contains all the coagulation factors, albumin and a source of plasma cholinesteraseIt is frozen within 8 hours and may be stored for up to 1 year at -30 ̊C. Under these conditions, the loss of Factors V and VIII is kept to a minimumThe frozen plasma can be thawed using a dry oven (10 minutes), microwave (2-3 minutes) or a water bath (20 minutes)Thawed FFP is best used immediately but may be stored at 4 ̊C and infused within 24 hours, provided it is kept at this temperature or returned to the blood bank for storage within 30 minutes of being removed from a 4 ̊C fridge or transport box.4-5 platelet concentrates, 1 unit single-donor apheresis platelets, or 1 unit fresh whole blood provide a quantity of coagulation factors similar to that contained in 1 unit FFPThe dose is ml.kg-1 (equivalent to three to four 300-ml packs of FFP)

15 HAS Available as 4.5% and 20% (salt poor albumin) solutionContain mmol/L sodium, latter contains less sodium per gram of albuminAlbumin is heat-treated to kill virusesIt has a shelf life of 2 years and stored at room temperature

16 ImmunoglobulinIVIG is sourced from a plasma pool of donors and provides polyclonal immunoglobulins to a wide variety of pathogensAnti-D immunoglobulin is prepared from the plasma of donors who have high levels of anti-D either following exposure to RhD positive cells during pregnancy or intentional immunisation

17 Cross-matchingCross-matching refers to the testing for compatibility before transfusionDetermined by ABO, Rh, KellElectronic cross-matching relies on computer analysis of tests done on the donor unit of blood and blood samples from the intended recipientSerological cross-matching requires that red blood cells from the donor blood are suspended in serum from the patient (recipient)